Table 1 Vaccination, screening, cost parameters and transition probabilities

Vaccination

Cohort size

25,000

Vaccine coverage

100%

Age at vaccination

12

Vaccine efficacy* - bivalent vaccine

87.2%

70%-95%

Vaccine efficacy* - quadrivalent vaccine

78.8%

70%-95%

Duration of efficacy

Lifetime

5 years to lifetime

Vaccine waning + booster

None

5, 10, 20 years

Screening

Screening age range

25-65

Screening interval

every 3 years

Percentage screened per year

17%

10-20

Cytology sensitivity to detect CIN1

0.58

none

Cytology sensitivity to detect CIN2/3

0.61

none

Compliance to CIN1 treatment

75%

50%-100%

Compliance to CIN2/3 treatment

75%

50%-100%

Cancer detection rate

Low

High

Probability Of symptons CC1

0.075

0.185

Probability Of symptons CC2

0.113

0.3

Probability Of symptons CC3

0.3

0.75

Probability Of symptons CC4

0.45

0.8

Cost, SGD$ (2008)

(-20%/+50%) except vaccine cost (200-400)

Vaccine cost per vaccinated woman, bivalent vaccine #

400

Vaccine cost per vaccinated woman, quadrivalent vaccine#

400

Cytology test^

40

Colposcopy and Biopsy^

207

CIN 1 treatment

1,105

CIN 2/3 treatment

1,480

Stage 1 Cancer treatment cost

9,388

Stage 2 Cancer treatment cost

9,765

Stage 3 Cancer treatment cost

9,765

Stage 4 Cancer treatment cost

11,047

Genital warts

750

Discounting

Costs, Outcomes

3%, 3%

(0%-5%)

Transition Probabilities

Well to HPV

0.05

0-0.2

HPV to clearance

0.4

0.29-0.55

HPV to CIN1

0.05

0.014-0.14

CIN1 clearance

0.4

0.24-0.5

CIN1 to CIN2/3

0.09

0.02-0.32

CIN2/3 clearance

0.25

0.01-0.45

CIN2/3 to persistent CIN2/3

0.11

0.03-0.20

Persistent CIN2/3 to Cancer stage 1

0.05

0.001-0.15

Cancer stage 1 to Cancer stage 2

0.22

0.11-0.4

Cancer 1 to cancer cured

0.84

0.63-0.98

Cancer stage 1 to Cancer stage 3

0.24

0.12-0.5

Cancer 2 to cancer cured

0.66

0.49-0.83

Cancer stage 3 to Cancer stage 4

0.24

0.12-0.8

Cancer 3 to cancer cured

0.38

0.28-0.48

Cancer 4 to cancer cured

0.11

0.08-0.14

Detected CIN1 to well

0.9

0.8-1

Detected CIN1 to Detected CIN2/3

0.09

0.02-0.32

Detected CIN2/3 to Well

0.9

0.8-1

Detected CIN2/3 to Detected PCIN2/3

0.11

0.03-0.20

Detected PCIN2/3 to Cancer 1

0.05

0.001-0.15

Mortality of cervical cancer

0.11

Cervical Warts

Effectiveness of vaccination against warts

0.90

Cost of treatment

750

Well to low risk HPV

0.050

Low risk HPV to well

0.500

Low risk HPV to CIN1 low risk

0.036

Low risk HPV to warts

0.027

Warts to well

0.875

CIN1 low risk to well

0.500

CIN1 low risk to detected CIN 1 low risk

0.099

Detected CIN 1 low risk to well

0.950

QALYs

Disease free

1

Genital warts

0.96

0.91-0.99

Detected CIN

0.89

0.84-0.94

Cancer detected

Stage I

0.65

0.49-0.81

Stage II

0.56

0.42-0.70

Stage III

0.56

0.42-0.70

Stage IV

0.48

0.36-0.60

Cancer cured

0.94